Vacuum feed



Sept. 13, 1927.

A. P. 'PLAUT VACUUM FEED Filed Oct. -22 '1921 v alum/KM 0 5m ro 6706/ p/awi "min dmw

Patented Sept. 13, 1927.

UNITED STATES ANTOINE P. ILAUT,

ERTS BRASS MANUFACTURING CO OF DETROIT,

MICHIGAN.

0F DETROIT, MICHIGAN, ASSIGNOR OF ONE-HALF TO THE ROB- MICHIGAN, A CORPORATION or VACUUM FEED.-

Application filed October 22, 1921. Serial No. 509.758.

The invention relates to vacuum feeding apparatus, such, for instance, as is used in connection with motor vehicles for elevating the liquid fuel from the main tank or reservoir. It is the object of the invention to obtain an increased vacuum where the engine is operating under open throttle.

.end the invention consists in the construction as hereinafter set forth.

In the drawings:

Figure l is a diagram showing a vacuum feeding system, .to which my improvement is applied;

Figure 2 is a section through the connecting feeding system; I

Figure 3 is a plan Figure 4c is a sectional elevation through a modified connecting feeding system;

Figure 5 is a similar view at right angles to Figure 4.

A is the tank or container, B is the vacuum tank, C the fuel line leading from the tank A to the tank B, D the carburetor, E the fuel feeding line from the vacuum tank to the carburetor, and F the suction line from the manifold G to the tank B. It is usual to merely tap the suction line into the manifold, the suction being produced by the difference between the manifold pressure and atmospheric pressure. This is effective whenever the engine is operating under closed or partially closed throttle, but when the throttle is nearly or completely open, the pressure drop in the manifold is comparatively slight. Consequently, at times there is not sufficient vacuum for the elevation of the fuel.

To incease the vacuum when operating under the conditions just described, I have provided the suction line with a fitting which projects into the manifold to a point near the center thereof, where the velocity of the incoming mixture is greatest. The end of this projection is also fashioned so as to increase the vacuum, preferably by form ing a Venturi passage with the suction connection located at the point in theventurl of greatest pressure drop. Thus, as shown in Figures 2 and 3, H is the fitting provided with a nipple I for engaging a threaded aperture in the manifold and the nipple J for attachment to the vacuum conduit.- is an inwardly projecting portion of the fitting which terminates near the center of view thereof;

To this the manifold in a portion having a Venturi passage L therethrough. M is a passage connecting the interior of the fitting H with the V enturi passage L and opening into the latter in the throat thereof or at the point wherethe vacuum will be highest.

With the construction as described, in whenthe throttle is wide open, through the manifold will be traveling at high velocity, particularly in the center of the stream. This high velocity gas in passing through the Venturi opening L will create an increased pressure drop at the throat thereof, which is communicated through the passage M to the fitting H and the suction conduit conneced therewith. Thus the static pressure within the suction conduit is lower than that within the manifold, which will produce a. greater lifting effect upon the liquid fuel.

As shown in the modified construction of Figures 4 and 5, the fitting N upon the manifold 0 comprises the nipple P for threadedly engaging in the wall of the manifold, the nipple P to the vacuum conduit and the inwardl projecting portion or extension P which terminates near the center of the intake manifold. Q is a transverse passageway in the end of the extension P this passa eway having its axis substantially paral el to the path of direction of the mixture passing through the intake manifold and furthermore, openin into the manifold upon the rear side of t e extension Q is an axial passageway in the fitting for placing the passageway Q in communication with the vacuum conduit. As shown in Figure 5, the mixture passing through the intake manifold takes the direction indicated by the flow lines so that at the point vR directly in advance of the extension P of the fitting, there is an area of high pressure, while at the point B there is an area of low pressure due to the gases being deflected around the extension and forming a pocket immediately in rear thereof. The passageway Q in the fitting extension opens into this low pressure area and as a consequence, suction is communicated to the vacuum tank.

What I claim as my invention is:

1. In a vacuum feeding system, the combination with an intake manifold having an operation, the mixture passing adapted to be attached aperture therein, of a fitting secured to said manifold and having a cylindrical inner portion insertable through said aperture and extending into said manifold transverse to the direction of flow therethrough, said fitting containing a Venturi passage entirely Within the cylindrical inner portion and con taining also a suction passage connecting with the throat of said Venturi passage, said Venturi passage having its axis substantially parallel to the direction of current through said manifold.

2. In a vacuum feeding system, the comloination ith an intake manifold having a threaded aperture therein, of a removable fitting threadedlysecured to said manifold and having a cylindrical inner portion infsert'ablet'hrough said aperture andextending :axis substantially parallel to the direction of flow through said manifold.

3. In a vacuum feeding system the combination With an intake manifold having threaded aperture therein, of a fitting insertable through said aperture and threadedly engageable with said manifold, said fitting having a cylindrical portion extending into said manifold transverse to the direction of flow therethrough, said fitting being also provided With a Venturi passage extending transversely to the axis of said cylindrical portion and arranged entirely Within the peripheral contour thereof, and a suction pa sage extending longitudinally of said fitting and connecting the throat of said Venturi passage.

4. A vacuum fitting for an intake manifold comprising a threaded portion for engaging said manifold, an axially aligned cylindrical portion of not larger diameter than said threaded portion and containing entirely within the cylindrical. contour thereof a Venturi passagearranged transversely to the axis of said cylindrical portion.,,saidfittting being provided With a longitudinal passage connecting with the throat of said Venturi passage.

In testimony whereof I 'affix my signature.

ANTOINE P. PLAUT. 

